The classical XXZ triangular-lattice antiferromagnet shows both an Ising and a Berezinskii-Kosterlitz-Thouless transition, related to the chirality and the in-plane spin components, respectively. In this paper the quantum effects on the thermodynamic quantities are evaluated by means of the pure-quantum self-consistent harmonic approximation, which allows one to deal with any spin value through classical Monte Carlo simulations. We present data for the internal energy, the specific heat, the static spin correlation functions, and the in-plane correlation length for different values of the spin and of the exchange anisotropy. The quantum transition temperatures turn out to be smaller the smaller the spin, and agree with the few available theoretical and numeric al estimates. [S0163-1829(99)04234-4].
Thermodynamics of the quantum easy-plane antiferromagnet on the triangular lattice / L. CAPRIOTTI; A. CUCCOLI; V. TOGNETTI; R. VAIA; P. VERRUCCHI. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 60:(1999), pp. 7299-7303. [10.1103/PhysRevB.60.7299]
Thermodynamics of the quantum easy-plane antiferromagnet on the triangular lattice
CUCCOLI, ALESSANDRO;TOGNETTI, VALERIO;
1999
Abstract
The classical XXZ triangular-lattice antiferromagnet shows both an Ising and a Berezinskii-Kosterlitz-Thouless transition, related to the chirality and the in-plane spin components, respectively. In this paper the quantum effects on the thermodynamic quantities are evaluated by means of the pure-quantum self-consistent harmonic approximation, which allows one to deal with any spin value through classical Monte Carlo simulations. We present data for the internal energy, the specific heat, the static spin correlation functions, and the in-plane correlation length for different values of the spin and of the exchange anisotropy. The quantum transition temperatures turn out to be smaller the smaller the spin, and agree with the few available theoretical and numeric al estimates. [S0163-1829(99)04234-4].I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.